1. Field of the Invention
The present invention relates generally to modeling applications, and in particular, to a method, apparatus, and article of manufacture for creating and displaying detailed cross-sectional views in a roadway infrastructure model along arbitrary directions and across multi-segment paths simultaneously.
2. Description of the Related Art
Roadway infrastructure is typically modeled in software applications by building cross sections along a pathway. Cross sections may be designed at regular intervals along an alignment and the road model encapsulates this information to present a three-dimensional (3D) model to the user. In some situations such as roundabouts, cross sections along multiple paths may be part of the same roadway model.
As a part of the design process, civil engineers routinely create cross sectional views of the road model at various locations for model investigation and documentation purposes. It is easy to create a sectional view along one of the designed sections since it involves reproducing the designed section. Ordinarily, these cross sectional views are created by using an object that represents a cutting tool. The cutting tool represents where the cross sectional view will be created and in prior art implementations must be aligned parallel to cross sections as they exist in the drawing.
Frequently users would like to create a sectional view that does not coincide with the designed cross section. Examples include roadway intersections, models of cul-de-sacs, roundabouts, off ramps etc. In some of these examples, the cutting plane will not align with a cross section in the roadway model which means that a cross section cannot be created.
Another deficiency in the prior art relates to the creation of a cross section view where the ends of the cutting tool used to create the cross sectional view fall within or between two cross sections. In other words, the newly designed cross section does not extend through the roadway cross section, but falls within the roadway. The prior art solves such problems by adding a design cross section if it aligns with the cutting plane.
Accordingly, it may be noted that prior art design applications do not support cutting sections in cases where the cutting plane does not align with a designed cross section. Instead, a layered based approach is utilized. In this regard, typically, roadway infrastructure models consist of various layers (e.g., pavement layer, gravel layer, subbase layer, etc.). Prior art procedures involve creating a DTM (digital terrain model) surface for the top of each layer. Thereafter, to represent each layer, users create a delta surface between the two layers that enclose it. However, such a procedure requires significant user effort and is therefore not desirable.
In other words, when users design roadways, it is not possible to design every aspect of the road (e.g., that is several miles long). Accordingly, cross sections are designed at large intervals (e.g., every one hundred [100] feet) and the designer specifies how the cross section looks at each cross section. However, no information is defined at intermediate locations between the cross sections. Nonetheless, it is desirable for users to cut sections along arbitrary planes—in planes that do not align with the designed cross sections. Further, some cross sections may be organized to form complicated shapes (e.g., roundabouts, highway off-ramps, etc.). Prior art systems were only able to display the information at the specifically designed cross sections. Further, users had to create derivatives of a model in order to display cross sections accurately (e.g., a surface was created from a model, and the newly created surface was displayed in the cross section).
In view of the above, it is desirable to provide a means to generate section views of roadway infrastructure models along arbitrary directions (cutting planes) and also across multiple-segment paths (alignments) simultaneously. In addition, it is desirable to provide a methodology to generate fully capable 3D solids for infrastructure models.